Shape-cutting machine or the like



June 17, 1952 A. A. BERARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE y Filed Oct. 14, 1947 15 Sheets-Shes?I l June 17, 1952 A A, BERNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Filed Oct. 14, 1947 13 Sheess-SheeiI 2 flu/eww Filed Oct. 14, 1947 13 Sheets-Sheet 3 June 17, 1952 A, A, BERNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Junel 17, 1952 A. A. BERNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Filed oct. 14. 1947 13 sheets-sheet 4 June 17, 1952 A. A. BERNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Filed oct. .14. 1947 v l.1s ,sheets-Sheets June 17, 1952 A, A. BERNARD SHAPE-CUTTING MACHINE 0R THE LIKE:

13 Sheets-Sheet 6 Filed Oct. 14, 194'? Filed oct. 14, 194'? 15' sheetssheet 7 June 17 ,1952 A. A; BERNARD 2,600,723

SHAPE-CUTTING MACHINE OR THE LIKE June 17, 1952 A A, BRNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Filed Oct. 14, 1947 15 Sheets-Sheet 8 4Z||.f.'11|7/////// fa 9g sp man 1.9 Wulnfmglllhl Filed oct. 14. 1947 1s sheets-sheet 9 Jun? 17, 1.952 A. AfBERNARD 2,600,728

` SHAPE-CUTTING MACHINE OR THE LIKE June 17, 1952 A. A. BERNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Filed oct. 14, 1947 1s sheets-sheet 1o uf y///,if///////////////// June,17, 1952 A. A. BERNARD 2,600,728

I i SHAPE-CUTTING MACHINE OR THE LIKE Filed Oct. 14, 194'? 13 Sheets-Sheet ll June 17, 1952 A, A, BERNARD 2,600,728

SHAPE-CUTTING MACHINE OR THE LIKE Filed OCT.. 14,- 1947 13 Sheets-Sheel 12 June 17, l952 1 A. A. BERNARD 2,600,728

SHAPE-CUTTING MACHINE 0R THE LIKE Filed 0G12. 14, 1947 15 SheeLs-Sheei'I 15 .Zy-a/ n l r l( I /Z l ii l t i j x )i l l l N 1S S S l Z-df @ci o I Q l @l @lrw Patented June 17, 1.952

UNITED STATES PATENT OFFICE SHAPE-CUTTING MACHINE OR THE LIKE Arthur A. Bernard, Chicago, Ill.

Application October 14, 1947, Serial No. 779,711

25 Claims. (Cl. 33-27) The principal object of this invention is to provide a light, portable, low-cost, all-purpose shape-cutting machine for operating a cutting torch on a work piece that will:

1. Automatically orient the torch constantly with respect to the line of travel or the line to be cut, Whether straight or curved;

2. Do bevel cutting simultaneously with irregular shape cutting;

3. Follow a complex templet accurately and regardless of size;

4. Cut larger or smaller than a templet (plus or minus the templet);

5. Cut square corners;

6. Cut small, intricate curves;

7. Cut large and small circles without a templet; and

I8. Work in any position from horizontal to vertical, together with a lot of other features, some of which will be specifically discussed.

Generally speaking, this is accomplished by providing a tracing head or carriage including a turntable or single castor that vis rotatable through 860 degrees about its own axis and about a portable stabilizing base with respect to which it is otherwise freely movable back and forth through a selected distance and which is propelled by a pair of differentially driven traction rollers astride the axis of rotation of the turntable which grip the guide rail of a templet to propel the tracing head or carriage along and hold the torch at a constant distance above the work and constantly orient it with respect to the line of travel or the line to be cut.

Further objects and advantages of the invention will appear as the disclosure proceeds.

The preferred embodiment of the invention, which has been found practical, is shown in the accompanying drawings, in which:

Fig. 1 is a perspective view of the machine on a templet which will normally be resting upon a work piece or secured to a work piece to be cut;

Fig. 2 is a side elevation, partly in section, of the machine secured to a templet, which, in turn, is secured to a work piecein this instance, in upright or in vertical position;

Fig. 3 is a side elevation of the machine resting on a templet, which, in turn, is resting on a work piece to be cut;

Fig. 4 is a similar side elevation of the machine associated with an auxiliary base and a small templet secured to the base, all of which are resting on a work piece to be cut;

Fig. 5 is a side elevation of the machine on a familiar type of pedestal adjacent to a work table supporting a work piece and a templet;

Fig. 6 is a plan view showing the machine on a complex templet in which are included all of the common curves, angles, and inclines at the outside and a circle and some additional gures on the inside;

Fig. 7 is an enlarged sectional view on the line 1-1 of Fig. 3;

Fig, 8 is another enlarged sectional view taken on the line 8-8 of Fig. 3;

Fig. 9 is a transverse section across the stabilizing bar looking toward the left in Fig. 8 withk the control cabinet removed;

Fig. 10 is an enlarged elevation partly in section of the tracing head or carriage and the swivel ring in which the turntable is mounted;

Fig. 11 is a vertical section taken on the line lI-ll of Fig. 10;

Fig. 12 is a transverse section taken on the line Fig. 13 is a perspective view of one of the traction rollers and its driving shaft together with the adjustment by which it is made to grip the guiding rail of a templet or the endless track of an attachment;

Fig. 14 is a vertical section taken on the line |4-I4 of Fig. 11;

Fig. 15 is a vertical section on the line I5--l5 of Fig. 11;

Fig. 16 is a transverse section taken on the line l6-I6 of Fig. l0;

Fig. 17 is an enlarged fragment showing one way of swiveling the tracing head or carriage on the stabilizing bar;

Fig. 18 is a cross section on the line l8-I8 of Fig. 17;

Fig. 19 is a similar cross section of a modified form;

Fig. 20 is an enlarged detail showing the traction rollers with inclined or curved driving ribs;

Fig. 21 is a similar view showing the traction rollers with herringbone driving ribs;

Fig. 22 is an enlarged detail showing the arrangement of the torch for bevel cutting;

Fig. 23 is an enlarged elevation, partly in section, showing the carriage equipped with an attachment enabling it to be power driven without the aid of a guiding rail on the templet, or manually guided for free-hand cutting;

Fig. 24 is a side elevation of the same;

Fig. 25 is a side elevation of a heat resisting wheel used in the attachment shown in Figs. 23 and 24 for running close to the cutting torch;

Fig. 26 is a diagram showing the conventional' practice of using preheating flames arranged about a cutting jet;

Fig. 27 is a similar diagram showing how a single preheating torch performs the work of several in prior practice due to the automatic orientation afforded by this invention;

Fig. 28 is a diagram illustrating the manner in which the differentially driven traction rollers traverse a sharp bend in the guiding rail of the templet;

Fig. 29 is a perspective view showing the machine as arranged for cutting a large circle;

Fig. 30 is a similar perspective view showing the machine rigged to cut a small circle;

Fig. 31 is a perspective view of an attachment used in cutting small circles as illustrated in Fig. 30;

Fig. 32 is an auxiliary base or adapter used under the normal base of the machine in operations illustrated by Figs. 23, 24, 29, and 30;

Fig. 33 is a perspective view of an auxiliary base for under the machine in connection with a small templet in the arrangement illustrated in Fig. 4;

Figs. 34, 35, 36, 37, 38, 39, and 40 are perspective views of different forms of templets and templet attachments for use with the machine and the auxiliary base;

Figs. 41, 42, 43, 44, 45, 46, 47, and 48 are plan views illustrating the use of an auxiliary base and a small templet in cutting simple figures from a plate.

But these drawings and the specific description are used for the purpose of disclosure only, and are not intended to impose unnecessary limitations on the claims.

General Description In the preferred embodiment of the invention, there is a tracing head or carriage I (Figs. 1, 2, 3, 10, and 11) including a turntable `I'I (Figs. l0 and 11) rotatable through 360 degrees and supported by a single non-driven Wheel I2 through which the axis of the turntable passes so that the carriage can travel and swivel like a single castor.

It is maintained in upright position with respect to the work piece by a portable stabilizing base I3 (Figs. 1, 2, 3, 4, and 5) and an arm .I4 that is swiveled to both the turntable and the base and slidable with respect to the base.

This arrangement allows the carriage to revolve about and completely around the base and to approach it and to recede from it and (when the limit of the sliding movement of the bar is exceeded) to move the base and simultaneously revolve about it. The carriage may be said to have universal movement with respect to a templet I5 (Figs. 1, 2, and 3) or a workpiece AI6 (Fig. 4) on which the base is supported, or to a plane parallel to a work piece.

From this, it will be apparent that a cutting torch I'I carried by the carriage will have universal freedom of movement with respect to the work while being held at a predetermined distance from it and maintained in 'the appropriate position with respect to the line of travel or the line to be cut. And because of the single-castor freedom of the carriage, it can follow the guide rail of a templet through any configuration as an inside rail or an outside rail.

The tracing head or carriage (Figs. and 11) The purpose of the tracing head or carriage is to carry and `direct the torch I1, or other suitable tool; and, to that end, it is equipped with or includes a driving head I8 having traction rollers I9 adapted to grip a guiding rail 20 of a templet or the like to propel the head or carriage. It also has a motor 2| for driving the traction rollers I9 through special transmission gearing 22.

The turntable II, which is the intermediate or body portion of the carriage, is disk-like in form, and is swiveled to a turntable ring 23 by ball bearings 24 and a flanged ring 25 made fast to the under side of the table by bolts 26. The ring 23 is connected to one end of the arm I4 by means permitting the entire head to be swung about the axis of the arm to a position of rest on the side of the ring, or to present the torch nozzle for cleaning or changing.

The turntable has a vertical central bore or socket 21 to receive a cylindrical shank 28 on the upper portion of the driving head I8, which is made fast by set screws 29, thereby making the driving head readily detachable from the carriage.

The driving head (Figs. 10, 11, 13, and 14) The driving head is an oblong, rectangular piece forked at its lower end to receive the supporting wheel I2, which is held in place by pins 30 below and ball bearing races 3| above, the latter serving to support the driving head and with it the entire carriage on the wheel I2; and, to that end, they are held in place by bearing pins 32 extending across the fork of the driving head.

At each side of the supporting wheel I2, the driving head has a longitudinal bore 33 to receive the shafts 34 and 35 of the traction rollers I9. The shaft 34 is journalled on two Torrington needle bearings 36, and the shaft 35 is journalled at its upper end on a single Torrington needle bearing 31, the lower end vbeing journalled in a half bearing capable of being adjusted in order to regulate the space between the traction rollers I9 and provide appropriate gripping action on the guiding rail of the templet or the endless wheel of another attachment.

This arrangement is best shown .in Figs. 13 and 14, where it will appear that the lower lend of the ydriving head has 5a lateral bore 3'8 receivlng a cylindrical bearing 39 having a semi-'circular bearing seat 40 for the lower `end of vthe shaft 35. The bearing 39 is controlled by a thumb Yscrew 4I threaded through a spring bracket 42 made fast to the side of the fdriving head `by vbolts 43. The spring bracket'42 is designed with appropriate resiliency to give the correct pressure on the lower end of the Vshaft 38 at the right in Fig. 14 to insure the driving grip on the guiding rail 20, or other guiding'expedients. The pressure is adjusted by simply turning the adjusting screw 4I in the appropriate direction. The spring 42 will allow for and accommodate irregularities in the thickness of the rail, some of which are unavoidable in bending guiding rails in the conventional manner.

The driving gear In order to insure some ofthe important advantages of this invention, the traction rollers I9 must Vbe diiferentially driven; and, in order to serve economy and make it possible to bring the traction rollers close together, the arrangement of the diiferential gearing is of special importance. Heretofore, as in my prior application Ser. No. 580,225, led February 28, 1945, the differential was arranged with its axis at right angles to the driving shafts for 'the traction rollers. This -made 'it necessary to ybuild special gears at high cost, and, in addition, made it irnpossible to place the traction rollers as close together as is often desirable in many uses of the machine. According to the present invention, the transmission gearing, generally indicated at 22, includes differential gearing with its axis substantially vertical or parallel to the axes of the shafts 34 and 35. This brings the ring gear 44 in a horizontal position with its axis at one side of the axis of the turntable, which is between the axis of the shafts 34 and 35 and passes through the supporting wheel I2. By this means, one of the driving gears 45 drives a pinion 46 on the upper end of the shaft 35. and the other driving gear 41 drives an idler 48'. which, in turn, drives a pinion 49 in driving connection with the shaft 34 through the spacer 49a.

All of this gearing is assembled within the gear casing 91, somewhat rectangular in form, on top of the turntable II, and closed by a cover plate 98 on which the motor base 50 rests, and both of which are secured to the gear casing 91 by bolts 5|. The arrangement of the gearings and their bearings within the casing and the cover will be clear from an inspection of Figs. 11, l2, and 14 without specific description.

It will be sufcient to say that the motor 2| drives a pinion 52 through worm gearing 53, and the pinion 52 drives the ring gear 44 through gearing generally indicated by 54.

This arrangement of the differential makes it possible to fit each machine with an assortment of driving heads having different spacing of traction rollers I9, thereby making a single machine suited to a variety of different classes of work and a variety of templet guiding rails.

Idle position of the tracing head and carriage- When the machine is not in use, the carriage should be in a position to protect its various parts from injury, and particularly the cutting tip. To

that end, the swivel ring 23 is provided with a cylindrical shank 55 (Figs. 1'1 and 18) rotatably mounted in the plug 56 and secured in the adjacent end of the arm I4 by screws 51. The inner end of that plug is provided with ratchet teeth 58 to cooperate with a pawl 59 urged toward the teeth by springs 60 on a bolt 6I secured to the shank 55.

An alternative form of such mounting is shown in Fig. 19, in which the shank 55 is provided with spherical seats 62 to cooperate with balls 63 urged inwardly by a spring 64 compressed by a screw 65 threaded into the plug 56. This arrangement permits the tracing head and carriage to be turned through 90 degrees to a position of rest when it is out of use, or when the cutting tip is to be cleaned or changed, and readily returned to upright position for use afterwards. As indicated in Fig. 6, the side of the swivel ring 23 may be provided with a special tooth 66 on which the carriage end of the apparatus may rest.

The base The base, generally indicated by I3, is lan inverted, cup-like casting 61 having a central hub 68 threaded at 69 to receive fastening bolts when it is to be made fast as indicated by the bolts in Fig. 2.

The hub has a central bore 1I in which a pintle 12 is journalled on ball bearings 13. The upper end of the pintle carries a device sometimes referred to as a bracket, and which includes a forked head 14, the arms 15 of which receive screw threaded trunnionsv 16 entering sockets 11 in bars 18 (Figs. 7, 8, and 9) which serve as bases for two sets of New Departure ball bearing rollers 19 on pintles 80. Those sets of ball bearing rollers form a passageway in which the arm I4 may slide as the carriage moves to and from the base I3.

Each of the trunnions 16 has a ykerf 8| by which it may be adjusted to regulate the pressure of the ball bearing rollers 19 on the arm I4. and the adjusted pressure may be maintained by setting up the lock nuts 82.

The arm is here shown as square, seamless steel tubing, which has considerable resiliency, by virtue of which the two sets of four bearings each may be set up with considerable pressure while permitting the arm to be moved back and forth with a minimum of resistance. This contributes to the steadiness and stability of the machine.

In order .to x the effective length of the arm I4, there is provided a positive stop including a plug 83 having a shank 184 movable in one of the trunnions 16 and subject to pressure of an adjusting screw 85 on a ball 86.

It is contemplated that the length of the arm I4 will be made or extended to suit any particular conditions for use of the machine, and that there shall be a stop to prevent the arm from becoming inadvertently disengaged from the base. The arm can even be made in assorted lengths or in several pieces that may be readily secured together or taken apart. As a permanent limit to the movement of the arm away from the base, a round head screw 81 (Figs. 6 and 9) is inserted through the end of the arm in the path of one of the ball bearing rollers 19.

The control cabinet A control cabinet 88, consisting of a sheet metal box, is mounted on the base by slitting its sides at 89 to receive the trunnions 16, and it is made fast by screws 90 inserted into the ends of the bars 18 through elongated slots 9|, which permit the adjustments provided for without distorting the control cabinet.

In the control cabinet is mounted a control switch 92 in the form of a rheostat by which the speed of the motor 2| may be controlled and varied to suit the conditions and requirements of the particular work.

The control cabinet also forms a convenient place for connecting hose 93 which supply the gases to the cutting torch.

In the position that is shown in the drawing, the hose are generally self supporting, but in other positions as the carriage approaches the base I3 there is a tendency for them to droop to the side, and to prevent this there is provided a support consisting of side arms 94 hinged at 95 and bearing at their outer ends a loop 96 extending around the hose and the wiring leading from the control cabinet to the motor.

The mounting of the torch The torch body |00 is mounted on the carriage for both vertical and lateral adjustment to permit the space between the cutting tip and the work piece to be varied and to vary the location of the tip with respect to the central axis of the turntable. To this end, the torch body is passed through a circular barrel |0| having arms |02 astride the driving head I8 (Figs. 10 and 16) and having their free ends secured to a nut |03 for an adjusting screw |04. A bent spring |05 between the barrel IOI and the driving head tends to shift the barrel to the left in Figs. and'16, whereas the screw i114 may be adjusted to shift it to the right in opposition to the spring. By this means, the axis of the cutting tip may be set to the right 4or to the left of the axis of the turntable in Fig. 'l0 and thus make it cut larger or smaller than a templet, as indicated by the guide rail ZU-in the language of the trade, plus or minus 'the templet. I-t also permits the axis of the cutting tip to be aligned with the axis of one of the traction rollers 'I9 when a sharp bend is to be rounded, as will be discussed in connection with Fig. 28.

The vertical adjustment is achieved by means of a rack |06 on the upper lportion of the torch body cooperating with the pinion |1111 (Figs. 110 and 16) controlled by a knob 198.

In order to conveniently indicate va selected adjustment laterally with respect tothe axis of the turntable, one of the forks I.02 is provided with a scale I09 and the driving head is provided with a pointer IID directed at the scale. In this way, the adjusting screw IDI becomes in effect a micrometer by which the axis of the torch may be very accurately and quickly set.

General operation With the machine set up as illustrated on sheets l, 2, and 3 of the draw-ings, the preheating names are lit and adjusted. When the preheat brings the surface of the work piece to the proper temperature, the high pressure oxygen valve is opened, and the motor 2| is started.

The adjusting screw 4I having been set to provide the appropriate pressure of the traction rollers I9 on the guide rail 20 of the templet, the rollers will propel the carriage along the rail on the supporting wheel I'2.

The grip of the traction rollers :1:9 on the rail makes the carriage .take and rmaintain a lposition on a line between .the axes of the two rollers I9 at right angles .to the axis of the rail of the templet, whether vthat ybe a straight line or on a curve. When it is a straight line, the axes of the traction rollers are on a line at right angles to it. When it is on -a curve, they are on a line at right angles to the tangent to the curve between the rollers.

This automatically turns the carriage about the axis of the turntable and maintains the cutting jet in proper relation 'to 'the :line of travel or the line to vbe cut, whether-straight-or curved. For want of a better term, this is called orientation.

Due to the differential drive Ator the rollers L9, this orientation is preserved through .any complex templet rail without regard to size.

Fig. 6 is selected as an `example to show -.the variety of movements through which `the traction rollers I9 will take the carriage with perfect orientation with respect to the line to be cut. At the upper left is an illustration of .gear teeth. Toward the lower corner from` that is a circle indicating the hole for a shaft. Following down the left side, there area variety Vof fcurves, .and at the lower side there is a .somewhat complex re-entrant cut with curves. Following .up .the right side are corners and .angles .of lvarious degrees. All of these are readily .followed by this machine.

In this gure, the machine is setto cut an internal complex 'figure indicated'by the rail III.

Fig. 28 indicates Adagrammatica'lly how the differentially driven 'traction 'rollers 'I9 enable the machine "to turn sharp curves or Leven substantially square corners. When `one of ythe driving rollers indicated 'by Athe 'position *H2 reaches the crux of the bend, the differential permits it to come to rest, while the other roller in the position I I3 speeds up to round the turn, automatically orienting the nozzle as it -proceeds and maintaining a fixed speed. In turning a corner in the opposite direction, the reverse would be true.

The inclined ribbed traction rollers In order to provide appropriate traction between the rollers and .the guide rail, they are provided with ribs or a knurled surface; but it is .a decided improvement to make the knurling or ribs on an incline or curve, as indicated at |14 in Fig. 20, or after the fashion -of what is known as herringbone I I5 in Fig. v21. These and other similar forms of inclined ribs or knurling effect a smoothness of rolling contact between the traction rollers and the side of .the rail, and eliminate what would otherwise .amount .to chattering, especially at speeds necessary in cutting heavy sheets.

In addition, by making the incline or curved ribs left and right, the traction rollers grip the rail with a downward pull or a pull toward the templet, pressing the supporting wheel I2 onto the top of the guiding rail and .thus maintaining the proper relation between 'the cutting torch and the work without the necessity of counterbalancing or providing spring pressure. This is of particular importance when .the `machine is used in a vertical position, or positions approaching that illustrated in Fig. 2.

The templet The templets shown in Figs. -l-.5 are vall equipped with legs or supports IIB of uniform length whereby there is provided a uniform lspace between the edge of the templetand the work in I which the torch Il may be freely adjusted .to

bring the cutting nozzle to the exact position required for the particular maneuver. Thus, in ordinary cutting along a straight line there is ample room, as shown in Fig. 10, to bring ythe axis of the torch tip in line with the axis of the turntable; and, where the work is to be cut smaller or larger than the templet, the axis of the tip may be adjusted laterally to suit. Also, in turning sharp curves or producing square corners, lthe axis of the tip may be `brought in line with the .axis of the traction roller on the inside of the curve or corner.

Bevel cutting Simplified preheating In conventional practice, the torch has a Vplu-- rality of preheating bores arranged Aabout a central oxygen bore. When cutting irregular iigures, or even a simple device 'like a rectangle, only vone of the preheating bores is aligned in advance of the oxygen bore. The others are largely wasted. This is illustrated ln Fig. 26,

9 where |60 indicates preheating bores and |6| indicates the oxygen bore.

Contrasted with this, in Fig. 27 a single preheating bore |62 is always in advance of and in line with the oxygen bore |63. That is made possible with this invention because of the constant orientation with respect to the line of travel or the line to be cut.

Beveled traction rollers The traction rollers I9, II4, and all have their lower corners |65 beveled, whereby they are easily brought into appropriate alignment with the guiding rail and spread apart against the resistance of the spring 42 by merely pressing the carriage downwardly.

The shafts 34 and 35 for the traction rollers are reduced at their lower ends to form a curved shoulder |10, which receives a washer |1| just above the traction rollers, which is notched at |12 to receive a cotter key |13 passing through the end of the respective shaft. This prevents localization of stresses in the area of the shoulder and adds greatly to the life of the shafts.

While the traction rollers may be made of a variety of materials, it has been found satisfactory to use tool steel and harden them 50 to 52 Rockwell C.

Special operation with templet joined to auxiltary base of the machine There are a great variety of cutting operations from very small pieces or small openings to great ones in which a machine of this invention has special advantages, and perhaps therein lies` its greatest usefulness. Instances to illustrate these are to be found in Figs. 4 and 34-48.

As illustrated in Fig. 4, the base |3 is resting upon an auxiliary base I to which a templet |2| is secured by bolts |22, the otherwise free end of the templet being equipped with supports ||6 of appropriate length. With a machine arranged on such a combination of auxiliary support and templet, the greatest variety of cutting operations, large and small, can be performed. Figs. 34 to 40 give examples of templets that may be assembled with the auxiliary base |20 and form a foundation on which the machine is isolated from surrounding conditions and performs its allotted cutting operations regardless of them. f

These expedients may be used to do shape cutting on various parts after fabrication, such as locomotive frames, tender frames, car sides, and such like. l 1

Also, these expedients can be used as illus- Y trated in Figs. 41-48 by bolting a suitable templet or templet element to an auxiliary base |20, which forms a unit that may be moved step by step along a sheet bearing the machine and maintaining it in proper operative condition while it repeats the same operation over and over again on the sheet. Figs. 41-44 illustrate selected operations of cutting cross shapes out` p variety of forms of such a combination are deemed too numerous to attempt to illustrate.

i Cutting without a templet manually or automatically guided With appropriate auxiliary attachments, the machine can be used for a great variety of cutting operations without a templet and guided either automatically or manually. Reference is made particularly to Figs. v23, 24, 25, and 29-32.

This sort of cutting is made possible by an auxiliary base |25, shown in Fig. 32, in conjunction with the special driving support shown in Figs. 23-25. l l

|21 indicates a forked pedestal-like bracket secured to the driving head I8 by cap screws |28 and having journal boxes |23 for a shaft |30 on needle bearings I 3| and equipped with wheellike endless track |32. -The shaft |30 projects toward the nozzle from the axis of the turntable and outside of the bracket |21 is equipped with a supporting wheel |33 close to the side of the torch tip I 34.

With this auxiliary support for thea carriage and the auxiliary base |25 (Fig. 32) for the base I3, the machine can do its cutting with manual guidance or automatic guidance. With manual guidance, it is important to have the wheel, |33 as close to the tip |34 as possible. In rounding curves or going from a tangent to a curve when it it close, as indicated in Fig. 23, the body portion or web of the wheel |35 should be made of heat resisting material such as chrome nickel steel, and preferably it is riveted to a flange |36 separated from the web by washers |31 of heat insulating material. Thus, the conduction of heat from the web to the body of the wheel is almost entirely through the small number of rivets, and is negligible.

For convenience in guiding the carriage in these manual operations, it is` provided with a hand wheel |16, shown in Figs. 10 and 11 as an extension of the base for the motor 2|.

For such operations as illustrated in Figs. 29 and 30, the auxiliary support for the carriage is also used to propel it, the traction rollers I9 being adjusted to grip the side faces of the rim |3,8,of

the wheel-like endless track |32. VIndeed for this operation the wheel-like endless trackmight be the support without the aid of the wheel |33.

In this operation, it isr convenient, if not necessary, to prevent the rotation ofthe carriage about the axis of the turntable, and to that end there is provided a latch |39 (Fig. 10) adapted to engage the keeper |40 to lock the turntable against rotary motion. With that latch in po- .,sition and the apparatus set up as illustrated in Fig. 29, the operation-is started as though a templet was being used, the traction rollers I0 driving the endless track or wheel |32 and making it travel in a circle as indicated by I-4| (Fig. 29), the adjusting screw |35 having been set up to prevent the arm I4 from moving with respect to the base I3. With'this arrangement, large circles of almost any dimension can be rapidly cut.

For small circles, the arrangement shown in Fig. 30 is very satisfactory. In this, there is added to the attachment of Figs.23 and 24 a device shown in Fig. 31 for confining the movement of the torch to a small circle. This deviceincludes side bars |42, shown as part of a yoke and operation, the adjusting screw 85 will be released in order to allow the arm I4 to slide back and forth in the bracket on the base I3.

In the apparatus as illustrated in Fig. 30, the operation is substantially the same as shape cutting with a templet, except that the traction rollers I9 propel the carriage through the wheellike track member 132.

This application is a continuation-in-part of my prior application Serial No. 580,225, filed February 28, 1945, now abandoned.

I claim:

l1. In a device of the class described, a tracing head, a pair of spaced traction rollers having substantially parallel axes for propelling the head, and means for driving the rollers including differential gearingwith its ring gear on an axis substantially parallel to the axes of the traction rollers and spaced laterally from the line joining the axes of said traction rollers and a supporting roller for the head between said traction rollers with its lower periphery above the bottom of the traction rollers.

2. In a device of the class described, a tracin head, a turntable therefor, propelling means for the head including a pair of spaced traction rollers, substantially parallel shafts for the rollers mounted on the turntable, differential gearing mounted on the turntable with the axis of its ring gear substantially parallel to said shafts and spaced laterally from the line joining the axes of said traction rollers, an idler between the differential and one of said shafts, and a nondriven wheel supporting the weight of said tracing head and turntable mounted between said shafts and having its lower periphery above the bottom of said traction rollers.

3. In a device of the class described, a tracing head, a turntable therefor, a pair of spaced traction rollers substantially parallel to the axis of the turntable, a swivel ring for the turntable, an arm substantially at right angles to the axis of the turntable, and a swivel connection between the ring and the arm.

4. In a device of the class described, a tracing head, a turntable therefor, a pair of spaced traction rollers substantially parallel to the axis of the turntable, a swivel ring for the turntable, an arm substantially at right angles to the axis of the turntable, a swivel connection between the ring and the arm, a base, and a slide bracket universally connected with the base and receiving the arm.

5. In a device of the class described, a tracing head, a turntable therefor, a pair of spaced traction rollers substantially parallel to and at each side of the axis of the turntable, a swivel ring for the turntable, an arm substantially at right angles to the axis of the turntable, a swivel connection between the ring and the arm, and means to latch the ring in a selected position.

6. In a device of the class described, a tracing head, and a pair of spaced substantially parallel traction rollers for the head, both of said rollers, having substantially continuous and unbroken oppositely inclined ribs on their traction surfaces, the traction surfaces of said rollers being substantially parallel to each other and to the surface engaged by them, and means for driving the rollers in opposite directions.

7. In a device of the class described, a tracing head, a turntable therefor, means for propelling the tracing head including a motor on the turntable driving through differential gearing a pair of traction rollers astride the axis Of' 12 the turntable and substantially parallel thereto, and a supporting roller for the head between said traction rollers with its lower periphery above the bottom of the traction rollers.

8. In a device of the class described, a tracing head, a turntable therefor, means for propelling the tracing head including a motor on the turntable driving through differential gearing a pair of traction rollers astride the axis of the turntable and substantially parallel thereto, a supporting roller for the head between said traction rollers with its lower periphery above the bottom of the traction rollers, and anti-friction bearings between the head and the periphery of said supporting roller.

9. In a device of the class described, a base, a templet connected with the base and having a guiding rail thereon, a slide bracket mounted on the base for limited universal movement, a guiding arm sliding in the bracket, a turntable connected With one end portion of arm, a tracing head mounting the turntable, and a pair of traction rollers for the head cooperating with the guiding rail on the templet.

10. In a device of the class described, a portable base, an arm mounted on the base to slide and to rotate through 360 degrees with respect to the base, a carriage including an annular bearing swiveled to one end of the arm, a turntable supported by said bearing to rotate through 360 degrees therein, a tool mounted on the turntable and movable therewith, a wheel supporting the carriage on the axis of the turntable, and a pair of driven traction rollers, one at each side of said wheel and said axis and parallel to said axis.

1l. In a device of the class described, a portable base, an arm mounted on the base for limited movement crosswise to and for rotation about the axis of the base, a carriage including an annular bearing swiveled to the arm, a turntable supported by said bearing to rotate about an axisl substantially parallel to the rst mentioned axis, a tool mounted on said turntable and extending through said bearing and movable with said carriage, and a pair of driven traction rollers to propel said carriage along a guiding track, one of said rollers being at each side of the axis of the turntable and both of said rollers being parallel to said axis.

12. A device as claimed in claim l1 in which the weight of the carriage is supported at the axis of the turntable by a single wheel mounted between the traction rollers, and in which the carriage is stabilized laterally by the arm and base.

13. In a device of the class described, a tracing head, a turntable therefor, a gear casing mounted on the turntable, propelling means for the head including a pair of spaced traction rollers, and a supporting roller for the head between said traction rollers with its lower periphery above the bottom of the traction rollers, substantially parallel shafts. for the rollers having their upper ends extending into the gear casing, differential gearing mounted in the casing including a ring gear having its axis parallel to said shafts and spaced laterally from the line joining the axes of the traction rollers, said gearing also including differentially driven, coaxial, vertically spaced spur gears, and means for driving said shafts. from said spur gears including spur pinions7 on said upper ends of the shafts and an idler interposedY between one. of said spur gears and the pinioned shaft4 which it drives.

14. In a device of the class described, a tracing head adapted to ride upon and be guided by a templet rail, a pair of differentially and oppositely driven, spaced traction rollers for gripping opposite sides of the rail to drive the head along the rail, a supporting wheel between the rollers adapted to ride upon the topof the rail and support the weight of the head, and substantially continuous ribs on the traction surface of at least one of the rollers, said ribs being inclined in a direction to exert a downward pressure on the supporting wheel.

15. In a device of the class described, a base, an arm mounted on the base for longitudinal movement relative thereto and pivoted for rotation through at least 360 about said base, a carriage mounted at one end of the arm with its weight carried on a single wheel and stabilized laterally by said arm and base, said carriage comprising a relatively large annular bearing, a turntable rotatably mounted in the bearing for rotation through 360", a tool extending through the bearing and carried by the turntable, and a power-driven traction device for moving the carriage about the base on said wheel.

16. In a device of the class described, a base, an arm mounted on the base for longitudinal movement relative thereto, a carriage mounted at one end of the arm with its weight carried on a single wheel, said carriage comprising a relatively large annular bearing, a turntable rotatably mounted in the bearing for rotation through 360, a tool extending through the bearing and carried by the turntable, a power-driven traction device for moving the carriage about the base on said wheel, and micrometer means for adjusting the position of the tool relative to the axis of the turntable.

17. In a device of the class described, a tracing head, means for driving the head including a pair of spaced, substantially parallel differentially driven shafts having a pair of traction rollers xed to the ends thereof, and resilient means for adjusting the alignment of one of the shafts with respect to the other, and hence the distance between the traction rollers,

18. In a device of the class described, a portable base, an arm mounted on the base to slide and to rotate through 360 with respect to the base, a carriage including a turntable swiveled to the arm to rotate through 360, Aa tool mounted on the turntable and movable therewith, a wheel supporting the carriage on the axis of the turntable, and a swivel connection between the carriage and the arm whereby the carriage may be rotated about the longitudinal axis of the arm.

19. A device of the character described for processing a workpiece having a relatively plane face, a tool for performing said processing operation, a turntable positioned parallel to said face and having means to support and carry said tool thereon whereby said tool will respond to all movements of said turntable, means aflixed to said turntable to support and move said turntable relative to said workpiece, a bearing porf Y' tion in which said turntable is journaled, an arm attached to said bearing portion, a base, and an arm-bearing means attached to said base to support the arm and to permit longitudinal movement of the arm with respect to said base about an axis substantially normal to said face and being limitedly rotatable with respect to said base about an axis substantially parallel to said plane face.

20. A device of the character described for processing a workpiece having a relatively plane face, a tool for performing said processing operation, a turntable positioned parallel to said face and having means to support and carry said tool thereon whereby said tool will respond to all movements of said turntable, means aiiixed to said turntable to support and move said turntable relative to said workpiece, abearing portion in which said turntable is journaled and through which said tool extends, an arm attached to said bearing portion, a base, an arm-bearing means attached to said base to support the arm and to permit longitudinal movement of the arm with respect to said base about an axis substantially normal to said face and being limitedly rotatable with respect to said base about an axis substantially parallel to said plane face, and means to urge said turntable in a direction toward said face.

21. In a shape-cutting machine, the combination of a self-propelled carriage adapted to follow a templet track and having a tracing head provided with power-driven, horizontally spaced, traction means including oppositely driven traction rollers engaging opposite sides of said track, tool means mounted on the carriage for movement therewith with its work-processing end p0- sitioned substantially in the vertical plane through the axes of the traction rollers, a relatively limited load-carrying surface on the head upon which the weight of the carriage is at least partially carried and being inadequate in area to give the carriage vertical stability, at least a portion of said load-carrying surface lying in said vertical plane, an annular vertical bearing in which the carriage is journaled and through which the tool means passes so constructed and arranged that the carriage with its tool means may freely rotate within the bearing through an angle of at least 360 degrees, and lateral stabilizing means for maintaining the carriage in upright position, said stabilizing means including a base and an arm secured to said bearing and movable about the axis of the base.

22. In a shape-cutting machine, the combination of a self-propelled carriage adapted to follow a templet track having a tracing head provided with power-driven, horizontally spaced, traction means including oppositely driven traction rollers engaging opposite sides of said track, a tool mounted on the carriage for movement therewith with its work-processing end positioned substantially in the vertical plane through the axes of the traction rollers, a relatively limited load-carrying surface on the head upon which the weight of the carriage is at least partially carried and being inadequate in area to give the carriage vertical stability, at least a portion of said load-carrying surface lying in said vertical plane, a vertical bearing in which the carriage is journaled so constructed and arranged that the carriage with its tool may freely rotate within the bearing through an angle of at least 360 degrees, said bearing having its axis substantially midway between the axes of the traction rollers, and lateral stabilizing means for maintaining the carriage in upright position, said stabilizing means including a base and an arm secured to said bearing and movable about the vertical axis of the base, said base having a horizontal pivot about which said arm may move.

23. In a device of the class described, a base, an arm mounted on the base for movement about the vertical axis of the base, an annular bearing carried at one end of the arm, a turntable supported by the bearing and freely rotatable 

